Abstract: Nitrogen is the key element among the major nutrients required in crop production and most of the Indian soils are deficient in this nutrient. To supplement nitrogen, along with other inorganic sources, extensive and continuous application of mineral fertilizers may cause imbalance in the soil micro flora in the long term and directly or indirectly influence the biological properties of soil. The Indo-Gangetic plains are located within the tropical and subtropical regions of India and are among the most agriculturally productive areas in the country. The average soil organic carbon content of the soils in the region is, however, low due to intensive cultivation along with prevailing high temperatures and humidity. Nitrogen is the major limiting plant nutrient in this region, with N availability being routinely supplemented through application of fertilizers. Soil organic N fractions were found to be affected markedly with nitrogen fertilization directly through changing the composition of soil N & indirectly through affecting crop growth.

Keywords: FYM, Fertilizer, Nitrogen Fraction, Crop Growth

| DOI: 10.17148/IARJSET.2019.6905